Conventional electronic document processing systems simply prevent an electronic document file to which such security information that prohibits edit, print, or copy of the document is attached from being imported into another electronic document file being edited, according to the security information. Also, a mechanism is known that circumvents security by invalidating security information attached to an electronic document file when one tries to import the electronic document into an electronic document file to be edited.
There are techniques that differentiate between printable and unprintable pages in an electronic document, such as the one disclosed in Japanese Patent Application Laid-Open No. 2003-162404.
The conventional electronic document processing systems have a problem that, because they prevent an electronic document file in which security information for preventing edit, print, or copy is set from being imported into another electronic document file on the basis of the security information, those files must be maintained separately for editing and thus their usability is degraded.
Another mechanism is known that circumvents security by invalidating security information attached to an electronic document file imported into another electronic document file to be edited.